Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

A potential loss of carbon associated with greater plant growth in the European Arctic


Rapid warming is expected to increase plant growth in the Arctic1, and result in trees gradually colonizing tundra2. Models predict that enhanced carbon (C) storage in plant biomass may help offset atmospheric CO2 increases and reduce rates of climate change2,3,4. However, in some Arctic ecosystems, high plant productivity is associated with rapid cycling and low storage of soil C (refs 1, 5, 6); thus, as plant growth increases, soil C may be lost through enhanced decomposition. Here we show that, in northern Sweden, total ecosystem C storage is greater in tundra heath (owing to greater soil C stocks) than in more productive mountain-birch forest. Furthermore, we demonstrate that in the forest, high plant activity during the middle of the growing season stimulates the decomposition of older soil organic matter. Such a response, referred to as positive priming, helps explain the low soil C storage in the forest when compared with the tundra. We suggest that, as more productive forest communities colonize tundra, the decomposition of the large C stocks in tundra soils could be stimulated. Thus, counter-intuitively, increased plant growth in the European Arctic could result in C being released to the atmosphere, accelerating climate change.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: C and N storage in the two ecosystems.
Figure 2: Seasonal variation in the 14C content of the respired CO2.
Figure 3: Respiration measurements and partitioning calculations.

Similar content being viewed by others


  1. ACIA Arctic Climate Impact Assessment Ch. 7 (Cambridge Univ. Press, 2005).

  2. Tape, K., Sturm, M. & Racine, C. The evidence for shrub expansion in Northern Alaska and the Pan-Arctic. Glob. Change Biol. 12, 686–702 (2006).

    Article  Google Scholar 

  3. Myneni, R. B., Keeling, C. D., Tucker, C. J., Asrar, G. & Nemani, R. R. Increased plant growth in the northern high latitudes from 1981–1991. Nature 386, 698–702 (1997).

    Article  CAS  Google Scholar 

  4. Qian, H., Joseph, R. & Zeng, N. Enhanced terrestrial carbon uptake in the Northern High Latitudes in the 21st century from the Coupled Carbon Cycle Climate Model Intercomparison Project model projections. Glob. Change Biol. 16, 641–656 (2010).

    Article  Google Scholar 

  5. Kane, E. S. & Vogel, J. G. Patterns of total ecosystem carbon storage with changes in soil temperature in boreal black spruce forests. Ecosystems 12, 322–335 (2009).

    Article  CAS  Google Scholar 

  6. Wilmking, M., Harden, J. & Tape, K. Effect of tree line advance on carbon storage in NW Alaska. J. Geophys. Res. 111, G02023 (2006).

    Article  Google Scholar 

  7. Ping, C. L. et al. High stocks of soil organic carbon in the North American Arctic region. Nature Geosci. 1, 615–619 (2008).

    Article  CAS  Google Scholar 

  8. Schuur, E. A. G. et al. Vulnerability of permafrost carbon to climate change: Implications for the global carbon cycle. BioScience 58, 701–714 (2008).

    Article  Google Scholar 

  9. Hobbie, S. E., Nadelhoffer, K. J. & Högberg, P. A synthesis: The role of nutrients as constraints on carbon balances in boreal and arctic regions. Plant Soil 242, 163–170 (2002).

    Article  CAS  Google Scholar 

  10. Hartley, I. P., Hopkins, D. W., Sommerkorn, M. & Wookey, P. A. The response of organic matter mineralisation to nutrient and substrate additions in sub-arctic soils. Soil Biol. Biochem. 42, 92–100 (2010).

    Article  CAS  Google Scholar 

  11. Mack, M. C., Schuur, E. A. G., Bret-Harte, M. S., Shaver, G. R. & Chapin III, F. S. Ecosystem carbon storage in arctic tundra reduced by long-term nutrient fertilization. Nature 431, 440–443 (2004).

    Article  CAS  Google Scholar 

  12. Wookey, P. A. et al. Ecosystem feedbacks and cascade processes: Understanding their role in the responses of Arctic and alpine ecosystems to environmental change. Glob. Change Biol. 15, 1153–1172 (2009).

    Article  Google Scholar 

  13. Laurila, T. et al. Seasonal variations of net CO2 exchange in European Arctic ecosystems. Theor. Appl. Climatol. 70, 183–201 (2001).

    Article  Google Scholar 

  14. Kullman, L. Early holocene appearance of mountain birch (Betula pubescens ssp. tortuosa) at unprecedented high elevations in the Swedish scandes: Megafossil evidence exposed by recent snow and ice recession. Arct. Antarct. Alp. Res. 36, 172–180 (2004).

    Article  Google Scholar 

  15. Tømmervik, H. et al. Above ground biomass changes in the mountain birch forests and mountain heaths of Finnmarksvidda, northern Norway, in the period 1957–2006. Forest Ecol. Manage. 257, 244–257 (2009).

    Article  Google Scholar 

  16. Sjögersten, S. & Wookey, P. A. The impact of climate change on ecosystem carbon dynamics at the Scandinavian mountain birch forest-tundra heath ecotone. Ambio 38, 2–10 (2009).

    Article  Google Scholar 

  17. Subke, J-A., Inglima, I. & Cotrufo, F. Trends and methodological impacts in soil CO2 efflux partitioning: A metaanalytical review. Glob. Change Biol. 12, 1–23 (2006).

    Article  Google Scholar 

  18. Trumbore, S. Carbon respired by terrestrial ecosystems—recent progress and challenges. Glob. Change Biol. 12, 141–153 (2006).

    Article  Google Scholar 

  19. Cardon, Z. G. Influence of rhizodeposition under elevated CO2 on plant nutrition and soil organic matter. Plant Soil 187, 277–288 (1996).

    Article  CAS  Google Scholar 

  20. Kuzyakov, Y. Review: Factors affecting rhizosphere priming effects. J. Plant Nutr. Soil Sci. 165, 382–396 (2002).

    Article  CAS  Google Scholar 

  21. Mitchell, R. J. et al. The cascading effects of birch on heather moorland: A test for the top-down control of an ecosystem engineer. J. Ecol. 95, 540–554 (2007).

    Article  CAS  Google Scholar 

  22. Subke, J-A. et al. Interactions between needle litter decomposition and rhizosphere activity. Oecologia 139, 551–559 (2004).

    Article  Google Scholar 

  23. Wardle, D. A., Nilsson, M-C., Gallet, C. & Zackrisson, O. An ecosystem perspective of allelopathy. Biol. Rev. 73, 305–318 (1998).

    Article  Google Scholar 

  24. Tybirk, K. et al. Nordic Empetrum dominated ecosystems: Function and susceptibility to environmental changes. Ambio 29, 90–97 (2000).

    Article  Google Scholar 

  25. Seastedt, T. R. & Adam, G. A. Effects of mobile tree islands on alpine tundra soils. Ecology 82, 8–17 (2001).

    Article  Google Scholar 

  26. McGuire, A. D. et al. Sensitivity of the carbon cycle in the Arctic to climate change. Ecol. Monogr. 79, 523–555 (2009).

    Article  Google Scholar 

  27. Freeman, S. et al. The SUERC AMS laboratory after 3 years. Nucl. Instrum. Meth. B 259, 66–70 (2007).

    Article  CAS  Google Scholar 

  28. Stuiver, M. & Polach, H. A. Reporting of 14C data. Radiocarbon 19, 355–363 (1977).

    Article  Google Scholar 

  29. Hardie, S. M. L., Garnett, M. H., Fallick, A. E., Rowland, A. P. & Ostle, N. J. Carbon dioxide capture using a zeolite molecular sieve sampling system for isotopic studies (13C and 14C) of respiration. Radiocarbon 47, 441–451 (2005).

    Article  CAS  Google Scholar 

  30. Harkness, D. D., Harrison, A. F. & Bacon, P. J. The temporal distribution of ‘bomb’ 14C in a forest soil. Radiocarbon 28, 328–337 (1986).

    Article  CAS  Google Scholar 

Download references


This work was carried out within the Natural Environment Research Council (NERC) funded Arctic Biosphere Atmosphere Coupling at Multiple Scales (ABACUS; project (a contribution to International Polar Year 2007–2008) under grants NE/D005833/1 and NE/D005884/1. We are grateful for the help of the staff at the Abisko Scientific Research Station. We thank L. English for assisting with the laboratory analyses, and J. Zaragoza-Castells and A. Bennett for their helpful comments on the manuscript.

Author information

Authors and Affiliations



P.A.W., I.P.H., D.W.H. and M.S. designed the study. Soil surveys were carried out by I.P.H., M.S. and P.A.W., and 14CO2 collection and analysis was led by M.H.G. The plant community surveys were designed and carried out by B.J.F., V.L.S. and G.K.P. All authors contributed to writing the manuscript.

Corresponding authors

Correspondence to Iain P. Hartley or David W. Hopkins.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Rights and permissions

Reprints and permissions

About this article

Cite this article

Hartley, I., Garnett, M., Sommerkorn, M. et al. A potential loss of carbon associated with greater plant growth in the European Arctic. Nature Clim Change 2, 875–879 (2012).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


Quick links

Nature Briefing Microbiology

Sign up for the Nature Briefing: Microbiology newsletter — what matters in microbiology research, free to your inbox weekly.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing: Microbiology